Fix for crashes when trying to delete a vertex in a polygon ring that has less than 3 vertices (bug 1041)

mhugent · mhugent · commit a0efa1ef8220 · 2008-04-17T07:22:08.000Z
git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@8358 c8812cc2-4d05-0410-92ff-de0c093fc19c
diff --git a/src/core/qgsgeometry.cpp b/src/core/qgsgeometry.cpp
@@ -1443,9 +1443,10 @@ bool QgsGeometry::deleteVertexAt(int atVertex)
     case QGis::WKBLineString:
       {
         int* nPoints = (int*)ptr;
-        if((*nPoints) < 3 || vertexnr > (*nPoints)-1 || vertexnr < 0)
+        if((*nPoints) < 3 || vertexnr > (*nPoints)-1 || vertexnr < 0) //line needs at least 2 vertices
         {
-          break;
+	  delete newbuffer;
+          return;
         }
         int newNPoints = (*nPoints)-1; //new number of points
         memcpy(newBufferPtr, &newNPoints, sizeof(int));
@@ -1498,9 +1499,10 @@ bool QgsGeometry::deleteVertexAt(int atVertex)
           //find out if the vertex is in this line
           if(vertexnr >= pointindex && vertexnr < pointindex + (*nPoints))
           {
-            if(*nPoints < 3)
+            if(*nPoints < 3) //line needs at least 2 vertices
             {
-              break;
+	      delete newbuffer;
+              return false;
             }
             newNPoint = (*nPoints)-1;
           }
@@ -1557,7 +1559,8 @@ bool QgsGeometry::deleteVertexAt(int atVertex)
           {
             if(*nPoints < 5) //a ring has at least 3 points
             {
-              break;
+	      delete newbuffer;
+              return false;
             }
             newNPoints = *nPoints - 1;
           }
@@ -1634,7 +1637,8 @@ bool QgsGeometry::deleteVertexAt(int atVertex)
             {
               if(*nPoints < 5) //a ring has at least 3 points
               {
-                break;
+		delete newbuffer;
+                return false;
               }
               newNPoints = *nPoints - 1;
             }

Original file line number	Diff line number	Diff line change
`@@ -1443,9 +1443,10 @@ bool QgsGeometry::deleteVertexAt(int atVertex)`
`1443`	`1443`	`case QGis::WKBLineString:`
`1444`	`1444`	`{`
`1445`	`1445`	`int* nPoints = (int*)ptr;`
`1446`		`- if((nPoints) < 3 \|\| vertexnr > (nPoints)-1 \|\| vertexnr < 0)`
	`1446`	`+ if((nPoints) < 3 \|\| vertexnr > (nPoints)-1 \|\| vertexnr < 0) //line needs at least 2 vertices`
`1447`	`1447`	`{`
`1448`		`- break;`
	`1448`	`+ delete newbuffer;`
	`1449`	`+ return;`
`1449`	`1450`	`}`
`1450`	`1451`	`int newNPoints = (*nPoints)-1; //new number of points`
`1451`	`1452`	`memcpy(newBufferPtr, &newNPoints, sizeof(int));`
`@@ -1498,9 +1499,10 @@ bool QgsGeometry::deleteVertexAt(int atVertex)`
`1498`	`1499`	`//find out if the vertex is in this line`
`1499`	`1500`	`if(vertexnr >= pointindex && vertexnr < pointindex + (*nPoints))`
`1500`	`1501`	`{`
`1501`		`- if(*nPoints < 3)`
	`1502`	`+ if(*nPoints < 3) //line needs at least 2 vertices`
`1502`	`1503`	`{`
`1503`		`- break;`
	`1504`	`+ delete newbuffer;`
	`1505`	`+ return false;`
`1504`	`1506`	`}`
`1505`	`1507`	`newNPoint = (*nPoints)-1;`
`1506`	`1508`	`}`
`@@ -1557,7 +1559,8 @@ bool QgsGeometry::deleteVertexAt(int atVertex)`
`1557`	`1559`	`{`
`1558`	`1560`	`if(*nPoints < 5) //a ring has at least 3 points`
`1559`	`1561`	`{`
`1560`		`- break;`
	`1562`	`+ delete newbuffer;`
	`1563`	`+ return false;`
`1561`	`1564`	`}`
`1562`	`1565`	`newNPoints = *nPoints - 1;`
`1563`	`1566`	`}`
`@@ -1634,7 +1637,8 @@ bool QgsGeometry::deleteVertexAt(int atVertex)`
`1634`	`1637`	`{`
`1635`	`1638`	`if(*nPoints < 5) //a ring has at least 3 points`
`1636`	`1639`	`{`
`1637`		`- break;`
	`1640`	`+ delete newbuffer;`
	`1641`	`+ return false;`
`1638`	`1642`	`}`
`1639`	`1643`	`newNPoints = *nPoints - 1;`
`1640`	`1644`	`}`